"Microsoft recently made a change to the licence agreement saying that a new motherboard is equal to a new computer, hence you need to purchase a new Windows licence. Here is what Microsoft has to say: "An upgrade of the motherboard is considered to result in a 'new personal computer' to which Microsoft OEM operating system software cannot be transferred from another computer. If the motherboard is upgraded or replaced for reasons other than a defect, then a new computer has been created and the license of new operating system software is required." Please note that this does not go for retail copies of Windows, but only for OEM versions.

Industries which are dominated by a single firm may allow the firm to act as a near-monopoly or "de facto monopoly", a practice known in economics as monopolistic competition. Common historical examples arguably include corporations such as Microsoft and Standard Oil (Standard's market share of refining was 64% in competition with over 100 other refiners at the time of the trial that resulted in the government-forced breakup). Practices which these entities may be accused of include dumping products below cost to harm competitors, creating tying arrangements between their products, and other practices regulated under antitrust law."